In this guided exercise, we will troubleshoot and resolve issues reported on an IPv4 network. First, we will launch the GNS3 network emulator and load the network environment for this lab.
Our first issue is with Linux-A in the 192.168.1.0/24 network. The user was told to install a Samba client and then attach to an SMB share on the FILESERVER host. The user says they are not able to install a Samba client. They report the following error:
Note: We are using the Alpine Linux distribution in this lab. The apk command performs the same function as apt in Ubuntu or yum in RedHat.
The message "temporary error" indicates a network problem. While this may initially seem a bit cryptic, we will use basic network troubleshooting to resolve the issue.
Next, you are told that the user on Linux-B in the 10.10.10.0/24 network cannot connect to the Internet. According to the local system administrator, they just switched clients to DHCP for this network.
With another network troubleshooting victory under your belt, you get a call from the 192.168.1.0/24 system administrator. The user on Linux-A cannot connect to FILESERVER using the Samba client you just installed for them. It seems no good deed goes unpunished! Then again, we should have tested that before declaring victory.
It's time for some well-earned cup of coffee, or so you think. The system administrator for 10.10.10.0/24 has a new issue. The Linux-B user can't reach FILESERVER either. You know that 192.168.1.0/24 and 10.10.10.0/24 are connected by the two firewalls using an IPsec VPN. You aren't an IPsec expert, but someone has to look into this.